This invention relates to a character recognition apparatus, method and computer readable memory for recognizing characters on the basis of a plurality of entered strokes.
In order to realize a character recognition method that is independent of the stroke order of a character in recognition of characters entered using a coordinate input unit such as a digitizer, recognition is carried out by matching each stroke constituting the entered character with a dictionary that has been previously stored in a memory device such as a hard disk. (By way of example, the dictionary stores character codes of standard characters expressed by, say, a table of Chinese characters in common use, and information on the strokes constructing these characters.) Since matching is performed on a stroke-by-stroke basis according to this method, recognition time, which is that required to recognize an entered character, is proportional to the square of the number of strokes of the character.
Accordingly, a method has been proposed, as set forth in the specification of Japanese Patent Publication No. 4-65431, in which the strokes of an entered character are matched with some of the strokes of dictionary strokes (e.g. dictionary strokes corresponding to the number of entered strokes and dictionary strokes over a range of one stroke before to one stroke after a given stroke). Though this method is not perfect, recognition independent of the stroke order is made possible, thereby shortening recognition time.
However, according to the matching method used in character recognition disclosed in Japanese Patent Publication No. 4-65431, basically matching is carried out on the basis of the stroke order of the entered character. Consequently, with regard to a character such as "E" which may be entered by the user in a completely incorrect stroke order, it is not possible to achieve high-speed character recognition that is independent of stroke order.